crypto/ec/ecx_backend.c

   1 /*
   2  * Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <string.h>
  11 #include <openssl/core_names.h>
  12 #include <openssl/params.h>
  13 #include <openssl/ec.h>
  14 #include <openssl/rand.h>
  15 #include <openssl/err.h>
  16 #ifndef FIPS_MODULE
  17 # include <openssl/x509.h>
  18 #endif
  19 #include "crypto/ecx.h"
  20 #include "ecx_backend.h"
  21
  22 /*
  23  * The intention with the "backend" source file is to offer backend support
  24  * for legacy backends (EVP_PKEY_ASN1_METHOD and EVP_PKEY_METHOD) and provider
  25  * implementations alike.
  26  */
  27
  28 int ossl_ecx_public_from_private(ECX_KEY *key)
  29 {
  30     switch (key->type) {
  31     case ECX_KEY_TYPE_X25519:
  32         ossl_x25519_public_from_private(key->pubkey, key->privkey);
  33         break;
  34     case ECX_KEY_TYPE_ED25519:
  35         if (!ossl_ed25519_public_from_private(key->libctx, key->pubkey,
  36                                               key->privkey, key->propq)) {
  37             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
  38             return 0;
  39         }
  40         break;
  41     case ECX_KEY_TYPE_X448:
  42         ossl_x448_public_from_private(key->pubkey, key->privkey);
  43         break;
  44     case ECX_KEY_TYPE_ED448:
  45         if (!ossl_ed448_public_from_private(key->libctx, key->pubkey,
  46                                             key->privkey, key->propq)) {
  47             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
  48             return 0;
  49         }
  50         break;
  51     }
  52     return 1;
  53 }
  54
  55 int ossl_ecx_key_fromdata(ECX_KEY *ecx, const OSSL_PARAM params[],
  56                           int include_private)
  57 {
  58     size_t privkeylen = 0, pubkeylen = 0;
  59     const OSSL_PARAM *param_priv_key = NULL, *param_pub_key;
  60     unsigned char *pubkey;
  61
  62     if (ecx == NULL)
  63         return 0;
  64
  65     param_pub_key = OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PUB_KEY);
  66     if (include_private)
  67         param_priv_key =
  68             OSSL_PARAM_locate_const(params, OSSL_PKEY_PARAM_PRIV_KEY);
  69
  70     if (param_pub_key == NULL && param_priv_key == NULL)
  71         return 0;
  72
  73     if (param_priv_key != NULL) {
  74         if (!OSSL_PARAM_get_octet_string(param_priv_key,
  75                                          (void **)&ecx->privkey, ecx->keylen,
  76                                          &privkeylen))
  77             return 0;
  78         if (privkeylen != ecx->keylen) {
  79             /*
  80              * Invalid key length. We will clear what we've received now. We
  81              * can't leave it to ossl_ecx_key_free() because that will call
  82              * OPENSSL_secure_clear_free() and assume the correct key length
  83              */
  84             OPENSSL_secure_clear_free(ecx->privkey, privkeylen);
  85             ecx->privkey = NULL;
  86             return 0;
  87         }
  88     }
  89
  90
  91     pubkey = ecx->pubkey;
  92     if (param_pub_key != NULL
  93         && !OSSL_PARAM_get_octet_string(param_pub_key,
  94                                         (void **)&pubkey,
  95                                          sizeof(ecx->pubkey), &pubkeylen))
  96         return 0;
  97
  98     if ((param_pub_key != NULL && pubkeylen != ecx->keylen))
  99         return 0;
 100
 101     if (param_pub_key == NULL && !ossl_ecx_public_from_private(ecx))
 102         return 0;
 103
 104     ecx->haspubkey = 1;
 105
 106     return 1;
 107 }
 108
 109 ECX_KEY *ossl_ecx_key_dup(const ECX_KEY *key, int selection)
 110 {
 111     ECX_KEY *ret = OPENSSL_zalloc(sizeof(*ret));
 112
 113     if (ret == NULL)
 114         return NULL;
 115
 116     ret->libctx = key->libctx;
 117     ret->haspubkey = key->haspubkey;
 118     ret->keylen = key->keylen;
 119     ret->type = key->type;
 120
 121     if (!CRYPTO_NEW_REF(&ret->references, 1))
 122         goto err;
 123
 124     if (key->propq != NULL) {
 125         ret->propq = OPENSSL_strdup(key->propq);
 126         if (ret->propq == NULL)
 127             goto err;
 128     }
 129
 130     if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
 131         memcpy(ret->pubkey, key->pubkey, sizeof(ret->pubkey));
 132
 133     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0
 134         && key->privkey != NULL) {
 135         if (ossl_ecx_key_allocate_privkey(ret) == NULL) {
 136             ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
 137             goto err;
 138         }
 139         memcpy(ret->privkey, key->privkey, ret->keylen);
 140     }
 141
 142     return ret;
 143
 144 err:
 145     CRYPTO_FREE_REF(&ret->references);
 146     ossl_ecx_key_free(ret);
 147     return NULL;
 148 }
 149
 150 #ifndef FIPS_MODULE
 151 ECX_KEY *ossl_ecx_key_op(const X509_ALGOR *palg,
 152                          const unsigned char *p, int plen,
 153                          int id, ecx_key_op_t op,
 154                          OSSL_LIB_CTX *libctx, const char *propq)
 155 {
 156     ECX_KEY *key = NULL;
 157     unsigned char *privkey, *pubkey;
 158
 159     if (op != KEY_OP_KEYGEN) {
 160         if (palg != NULL) {
 161             int ptype;
 162
 163             /* Algorithm parameters must be absent */
 164             X509_ALGOR_get0(NULL, &ptype, NULL, palg);
 165             if (ptype != V_ASN1_UNDEF) {
 166                 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
 167                 return 0;
 168             }
 169             if (id == EVP_PKEY_NONE)
 170                 id = OBJ_obj2nid(palg->algorithm);
 171             else if (id != OBJ_obj2nid(palg->algorithm)) {
 172                 ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
 173                 return 0;
 174             }
 175         }
 176
 177         if (p == NULL || id == EVP_PKEY_NONE || plen != KEYLENID(id)) {
 178             ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
 179             return 0;
 180         }
 181     }
 182
 183     key = ossl_ecx_key_new(libctx, KEYNID2TYPE(id), 1, propq);
 184     if (key == NULL) {
 185         ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
 186         return 0;
 187     }
 188     pubkey = key->pubkey;
 189
 190     if (op == KEY_OP_PUBLIC) {
 191         memcpy(pubkey, p, plen);
 192     } else {
 193         privkey = ossl_ecx_key_allocate_privkey(key);
 194         if (privkey == NULL) {
 195             ERR_raise(ERR_LIB_EC, ERR_R_EC_LIB);
 196             goto err;
 197         }
 198         if (op == KEY_OP_KEYGEN) {
 199             if (id != EVP_PKEY_NONE) {
 200                 if (RAND_priv_bytes_ex(libctx, privkey, KEYLENID(id), 0) <= 0)
 201                     goto err;
 202                 if (id == EVP_PKEY_X25519) {
 203                     privkey[0] &= 248;
 204                     privkey[X25519_KEYLEN - 1] &= 127;
 205                     privkey[X25519_KEYLEN - 1] |= 64;
 206                 } else if (id == EVP_PKEY_X448) {
 207                     privkey[0] &= 252;
 208                     privkey[X448_KEYLEN - 1] |= 128;
 209                 }
 210             }
 211         } else {
 212             memcpy(privkey, p, KEYLENID(id));
 213         }
 214         if (!ossl_ecx_public_from_private(key)) {
 215             ERR_raise(ERR_LIB_EC, EC_R_FAILED_MAKING_PUBLIC_KEY);
 216             goto err;
 217         }
 218     }
 219
 220     return key;
 221  err:
 222     ossl_ecx_key_free(key);
 223     return NULL;
 224 }
 225
 226 ECX_KEY *ossl_ecx_key_from_pkcs8(const PKCS8_PRIV_KEY_INFO *p8inf,
 227                                  OSSL_LIB_CTX *libctx, const char *propq)
 228 {
 229     ECX_KEY *ecx = NULL;
 230     const unsigned char *p;
 231     int plen;
 232     ASN1_OCTET_STRING *oct = NULL;
 233     const X509_ALGOR *palg;
 234
 235     if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8inf))
 236         return 0;
 237
 238     oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
 239     if (oct == NULL) {
 240         p = NULL;
 241         plen = 0;
 242     } else {
 243         p = ASN1_STRING_get0_data(oct);
 244         plen = ASN1_STRING_length(oct);
 245     }
 246
 247     /*
 248      * EVP_PKEY_NONE means that ecx_key_op() has to figure out the key type
 249      * on its own.
 250      */
 251     ecx = ossl_ecx_key_op(palg, p, plen, EVP_PKEY_NONE, KEY_OP_PRIVATE,
 252                           libctx, propq);
 253     ASN1_OCTET_STRING_free(oct);
 254     return ecx;
 255 }
 256 #endif